Sprinklers for irrigating plots of land have long been known in the art. Sprinklers generally comprise one or more nozzles which rotate and provide outflowing jets of water over a relatively large range. These sprinklers are generally large in size and relatively costly to manufacture. They include seals used for sealing and friction purposes and, therefore, are sensitive to dirt which can stop their rotation.
Miniature sprinklers are known which are constituted by a fixed nozzle attached by any suitable means to a water supply line. These nozzles are mounted opposite a rotating diverter, generally constituted by a disc, a rectangular element, or the like, which is provided with a diametrically extending channel, the ends of the channels being curved relative to the diameter in the same rotational sense. This curvature causes the jet from the nozzle to rotate the diverter and, in the opposite rotational sense, directs the outflowing water so that it irrigates the circular area surrounding the nozzle. Thus, the same element which divides the flow also serves to cause rotation of the diverter.
While these miniature sprinklers are small in size and relatively inexpensive to manufacture, they suffer from a number of disadvantages. They rotate at very high speed so the water outflow therefrom is in the form of droplets, not a jet. They can only be used in areas which are protected from the wind. Their range is small (i.e., 10 meters), and the relatively small droplets spread thereby often lack sufficient force to penetrate through the leaves of the plants they are required to irrigate. Another disadvantage is that the outlet channels remain open then the sprinkler is not in operation, and insects and foreign matter often enter the nozzle through the channels and clog the sprinkler.
A solution to the latter problem of insects entering the open outlet channels has been proposed including a bath-like element disposed beneath the rotating diverter. The diverter is arranged for vertical movement within the bath whereby, when the water is turned off, the entire rotating diverter is retracted into the bath. Due to the size of the bath element, it is complicated to adapt the device to existing sprinkler systems, requiring modification of the bridge member, which in turn attracts pests which damage the sprinkler. Furthermore, this element is complicated to manufacture, assemble and disassemble, and requires substantial maintenance.